Dermatology

Abscess

Are You Confident of the Diagnosis?

A cutaneous abscess is a localized collection of purulent material. It is most commonly a manifestation of a staphylococcal infection. Abscesses are commonly located in the axillae, groin, and rectal area, but can be located in any area.

Characteristic findings on physical examination

On physical examination, they are characterized as fluctuant subcutaneous collections, with overlying erythema and edema (Figure 1). During drainage of an abscess, a bacterial culture can be obtained in order to determine the causative pathogen.

Figure 1.

MRSA abscess.

Diagnosis confirmation

The diagnosis can usually be made on clinical observation. The differential diagnosis includes inflamed cysts (lesions often display a pore if they are epidermoid cysts), hidradenitis suppurativa (often as part of the “follicular occlusion tetrad” of hidradenitis, dissecting cellulitis, acne vulgaris, and pilonidal cysts; lesions typically in the axillae and inguinal regions), furuncles (follicularly derived abscesses) and carbuncles (derived from multiple follicles).

Who is at Risk for Developing this Disease?

Abscesses can develop in any individual; however, immunosuppression increases the risk for abscesses. Individuals with the following conditions or on the following medications are at greater risk: chronic steroid therapy, chemotherapy, malignancies, dialysis for kidney failure, AIDS, sickle cell disease, peripheral vascular disease, inflammatory bowel disease, and severe burns.

What is the Cause of the Disease?

Etiology

Pathophysiology

The most common bacterial organism responsible for the development of skin abscesses is Staphylococcus aureus, although various other organisms can also lead to abscess formation. With the emergence of methicillin-resistant S aureus (MRSA), healthcare providers must now consider this organism as the possible cause when a skin abscess is encountered.

Systemic Implications and Complications

Most abscesses are localized and lead to no systemic complications. Rarely, systemic infections can result from complicated and untreated lesions.

Treatment Options

Treatment options are summarized in Table I.

Table I.

Topical

Systemic

Surgical

Adjunctive

Mupurocin ointment

Antistaphylococcal antibiotics

Incision and drainage

Decolonization with mupurocin ointment

Clindamycin

Warm compresses following incision and drainage

Hibiclens cleanser

Tetracyclines

Bleach baths

Trimethorprim-sulfamethoxasole

Benzoyl peroxide wash

IV antibiotics (clindamycin, oxacillin, vancomycin

Optimal Therapeutic Approach for this Disease

Incision and drainage has been proven to be the mainstay of treatment for abscesses and furuncles. Initial incision and drainage and treatment of skin abscesses without antibiotic treatment is not significantly associated with increased follow-up visits to a health care provider, subsequent incision and drainage, or change in antibiotic treatment. Empiric antibiotic therapy should be initiated as an adjunct to incision and drainage, particularly in cases with rapid progression, lesions greater than 5 cm, systemic manifestations, and in immunocompromised patients.

β-lactam antibiotics with antistaphylococcal and streptococcal activity are a reasonable initial treatment with careful follow-up in cases of mild skin and soft tissue infections (SSTIs) among otherwise healthy patients residing in areas with low MRSA prevalence. Oral non-β-lactam antibiotics should be initiated for patients with SSTIs unresponsive to initial incision and drainage and β-lactam antibiotics or cases with a high clinical suspicion of community-acquired MRSA. These non-β-lactam antibiotics include clindamycin, linezolid, tetracycline, and trimethoprim-sulfamethoxazole. In complicated cases, intravenous antibiotics, such as clindamycin, oxacillin, and vancomycin, may be required.

In individuals or groups, where there is suspicion of staphylococcal carriage, decolonization may be indicated. Application of mupurocin ointment to the nares, axillae, groin, and perineum can be utilized to eradicate colonization. In addition, antiseptic agents and dilute bleach baths may be utilized. A benzoyl peroxide cleanser may also be of value.

Patient Management

Patients should be followed for recurrences, which may signify persistent colonization with staphylococci. Repeated decolonization or referral to an infection disease specialist should be considered. Decolonization of family members and sexual contacts may be required. Decolonization should also be considered in the following scenarios: college dormitories, sports teams, and among military recruits.

Unusual Clinical Scenarios to Consider in Patient Management

Patients who are immunocompromised or have other comorbidities should be followed closely. Other groups who should be monitored closely include diabetics, those with atopic dermatitis, and individuals on isotretinoin. A systemic work-up should be considered in those with an unusually severe or recurrent presentation.